I hope this message finds you in good health during the pandemic. Daydreaming 🌈🌴🦋 of our move to STX has definitely been a good brain vacation for us both 🤪. Ideally, we would like to have a concrete roof when building in the future and curious if any of you can share your personal pros and cons to this topic. Also, if anyone has links or contractor they highly recommend for this project please do share. The square footage we have in mind is roughly 1200-1400 square feet. Any ballpark best guesstimate of just the roof cost would be helpful but understandable if too many things to factor in for an estimate.
Are you asking about concrete roof tiles or cast in place solid concrete?
@Scubadoo Hello 👋🏼 Cast in place is what I was imagining and did not realize they made concrete tiles as well. Cast in place would be stronger, yes? Is cast in place less likely to be damaged in hurricanes if cast in place if done properly?
A concrete roof? I don't know if its really worth it.
My standard wood roof has survived both Hugo and Maria.
A concrete roof might keep the house a few degrees cooler, or maybe not.
@vicanuck That is fantastic your standard wood roof has withheld through such strong storms. I worry so much of the roof blowing off even with no overhangs. My friends in STX have a poured concrete roof currently awaiting to build the second level (eventually) so it’s nothing beautiful right now but said it’s super strong and just brainstorming building ideas for us in the future. I guess is also depends maybe what part of the island you are located or just “which way the wind decides to blow” during the heaviest of storms? Our goal is build as strong as possible to go without wind insurance since we don’t plan to take loans out for building. If done proper do you feel standard wood roof is a better why to go? I am open to any and all feedback on the topic so whatever anyone has for us we greatly appreciate it!
What's important for any roof system is how well it's secured to the walls and foundation. A properly secured framed roof should be fine. Then you have to cover it with something. Not asphalt shingles, they won't hold up. Metal roof, perhaps if you can find one hurricane rated. Concrete roof tiles, they will hold up for 100 years. Expensive. Could get damaged by impact in a hurricane. Needs little maintenance but should be cleaned periodically. A simple membrane would also work. Would need periodic re-coating. A cast in place concrete roof may be more expensive up front but lower cost over many years.
Two words, Bond Beam.
All properly built homes have them here. A bond beam is built along the top of every 8” thick exterior cement block wall. It’s usually 18-24” in height, constructed of a steel cage (numerous sections of rebar) and cement. Every roof rafter gets drilled out and tied into the steel cage, before the cement is poured, which encases and binds everything together, and fills every other steel reinforced cinder block hole (floor to ceiling).
Wow! That certainly sounds secure! Investing in something that is incredibly durable and most reliable is very important to us. Is Bond Beam used for both poured concrete roof as well as standard wood roof designs? Another reason we are interested in as much concrete as possible is termites....we have read they usually don’t attack concrete (for the most part). I read a few of the threads on here with different preventative measures you can take each year to do your best to keep them from eating up the wood. Adding Bond Beams to our notebook 😁 Thank you!!
Not sure why everyone keeps trying to sell you wood rafters when you clearly want a concrete roof.
I have built over 20 buildings with concrete roofs here. They work great.
pros: when engineered and waterproofed properly (preferably with a heat welded Hypalon roofing system) they are low maintenance, last forever and are almost impervious to hurricanes.
cons: higher initial cost (but your house is small so might not be as big of an issue) and aesthetics (can be boxy, but having taller walls (9’ or taller) helps inside and adding parapets can improve the exterior view).
I’m not going to comment on price because I’m not in the residential market.
@nohstx I appreciate any and all feedback so it’s good for me to add to our notebook things to look into. Since you don’t do residential do you by any chance know of anyone that does you could put me in touch with so I can reach out to them directly for pricing?
I’d suggest doing a search for a reputable STX Architect first. The design work will be the first step on a very long, and guaranteed bumpy road. It’s imperative to get a local to help guide you through the process. They’ll be many hoops to jump through along the way.
Agreeing on a final design, along with Earth Change and building permits took about 6 months. Excavation alone took nearly 2 months (man power issues, heavy equipment breakdowns, waiting for parts). The actual construction was supposed to take 6 months, I’m currently approaching the 2 year mark. Granted, in the meantime, the world has gone upside down. More than anything else, you’ll find you won’t have the same number of options here as you do in the states. They’ll always be a lack of choices, whether for materials or capable, reliable, and available craftsmen.
More important than the amount of money you’ll spend, and you’ll spend more than you expect to, you will definitely need to bring a boat load of patience with you.
Another valuable use of bond beams is to tie the long walls of a house together to keep them from flexing in and out in a storm or earthquake (they're also called tie beams in this case). In my house, they are above (and incorporated into) the vertical walls that separate the main (living/dining/kitchen) area from the bedrooms and bathrooms on the ends of the house.
This additional set of reinforced beams makes the house much more rigid and able to withstand higher flexing and twisting forces by spreading them between the two long walls (reinforced with bond beams). It also helps maintain the proper spacing of the walls to keep the triangular cross section of your roof beams or trusses, reducing the force on the connections between the bond beams around the top of the walls and the roof rafters.
My company worked on a lot of roofs and homes after the storms. We saw a lot of roofs that were strong enough to handle the winds but were significantly damaged by flying debris. In one case, there was a home that had two 2x6 pieces of lumber pierce the metal, sheathing, and cladding like missiles. They still had enough force after they entered the house to break the tile floor. 😳
WOW!!! That sounds like a tornado did that. There was an Outside magazine article written after the 2017 hurricanes and in the article, someone said that they saw 7 tornadoes during Irma (which passed over STJ during the day)
I don't know that any type of building will withstand a direct tornado hit, or tornado strewn debris like what Julie mentions, unless it is a concrete box. Think about the concrete "safe rooms" that people now build in tornado prone areas.
Please, DO NOT consider building a home out of shipping containers.
There’s a reason HGTV doesn’t have “Five years Later” episodes.
We worry about the roof lifting off during heavy storms as well as any objects that could potentially pierce the roof as well. That is why we have been trying to research the poured cast in place roof option. We didn’t know there are also concrete tiles but we also worry about termites of course. I totally understand nothing is 100% hurricane or termite proof but the closest we can get to safest and longest lasting we prefer to invest in good materials for longevity. We plan to build only 1200 to maybe 1400 square feet which we feel is big enough but not too big for our needs. We are tying to find out if we build our ceiling high enough if having a loft area counts as second floor requiring a bigger cistern capacity as well. If anyone knows if a loft counts as second floor or not that would be great to know in advance! The loft is not a “must”. Just seeing what our options are. This blog/message center has given us more help in planning, awareness, referrals etc better than any Google Searches we can find! You are all so great and we like any and all feedback so thank you all very very much!
@stxdreaming1 Shipping containers I think would be a good idea in other areas but not STX. We read they can rust quite quickly also hot inside 🥵. We do enjoy looking at the creative ways people are building homes is different areas and saw some pretty interesting ones finished 😁 We want to build something very strong and to last a very long time (hopefully 🤭finger and toes crossed).
I think there are several considerations when it comes to building a home that can survive a major storm. Where you chose to build can have a big impact, being on a exposed beach versus being in a more protected area, for example. One story versus two can have an impact and obviously concrete construction versus stick built. Our home was built in 1970, so 50 years ago, it’s been through 4 or 5 “big ones” and has come through with out major damage. All our exterior and most interior walls are cement but our roof is wood, but is very well constructed. We’re also a one story house that’s tucked into the side of a hill, about 3/4 the way up the hill, affording us nice views with a degree of protection. My point is the site, site planning as well as the construction all come into play, for both safety and cost. As with most things in life there are trade-offs and no perfect answer. Good luck with your project.
All good points Jaldeborgh.
Another consideration is roof pitch. A flat roof (most cement roofs) are prone to upwelling in high winds. As 200 mph gusts travel over a near flat surface, lift is created (think airplane wing). My architect included an 8/12 pitch on my wood roof, supported by 3x8’s and 3x10’s set 24” apart. As explained to me, taller, more pitched roofs, gets pushed downward in high winds.
Out of interest, why do you say that? You think the conditions in the Caribbean wouldn't suit it? Surly if it was insulated correctly you wouldn't have an issue?
Isn't there a hotel/hostel on St John made from containers? Swear I saw that once a few years ago.
It’s not a question of insulation, they’re impractical because they wouldn’t hold up here. All sea containers are built in China of cheap corten steel. The rubber door seals dry rot, hinge bushings disintegrate, and the wood floors are treated with a toxic cocktail of insecticides. The steel and wood floors rot out at about the same time (15 years under the best of conditions), there’s a reason most sea containers are removed from service after 10-12 years. Do we all agree their ugly?
You’ll still need a foundation of some kind. A means of securing it to that foundation incase a Cat5 come to town. You’ll still need a cistern, plus a means of filling it. Run plumbing, electrical, gas lines. Etc, etc, etc...
A poured concrete roof will still require some kind of water protection coating that will need to be redone periodically. Normally people use an elastomeric paint that is rated for potable water applications, as you will most likely have a cistern(s). I have been up on several flat concrete roofs here and have never seen one yet that did not have areas of standing water, and elastomeric paint will not age well under puddles, even if they do evaporate after a day or two. You can use a silicone based coating in this areas, which is more expensive but will still require periodic replacement. A flat roof will also normally have embedded downspouts to the cistern, which may be the only way to remove water from the roof. You will still probably need to pressure wash your roof on occasion and it is difficult to block off the downspouts so that water does not go into your cistern. And finally, it appeared to me from riding around the island after Maria that the majority of heavily damaged roofs were corrugated metal roofs, which is a relatively inexpensive roofing material for good reason. While I certainly had friends and knew of others who had what appeared to be well built homes with other roof materials that did suffer roof damage, there appeared to be a pretty strong correlation between quality of construction and major roof damage.